Proper cable selection is a key factor in the construction cost, safety, and system stability of EV chargers. This guide explains how to calculate charging current and select suitable cables for AC and DC charging systems.
1. Charging Current Calculation
Single-phase charging (AC EV charger)
For a single-phase AC EV charger, the current calculation formula is:
I = P / (U × 0.85)
Three-phase charging (DC EV charger)
For a three-phase DC EV charger, the current calculation formula is:
I = P / (U × 1.732 × 0.85)
2. AC Charging Cable Selection
The table below shows reference cable selection for AC EV chargers.
Power | Input Current | RCD Breaker | Copper Cable (YJV) | Aluminum Cable (YJLV) | Phase |
|---|---|---|---|---|---|
AC 3.5kW | ≤19A | 32A / 2P | 3×4 | 3×6 | Single-phase |
AC 7kW | ≤38A | 40A / 2P | 3×6 | 3×10 | Single-phase |
AC 14kW | ≤75A | 80A / 2P | 3×10 | 3×25 | Single-phase |
AC 11kW | ≤19A | 32A / 3P/4P | 5×4 | 5×6 | Three-phase |
AC 21kW | ≤38A | 40A / 3P/4P | 5×6 | 5×10 | Three-phase |
AC 42kW | ≤75A | 80A / 3P/4P | 5×10 | 5×25 | Three-phase |
3. DC Charging Cable Selection
3.1 Integrated DC Charger
The table below shows reference cable selection for integrated DC chargers.
Power | Input Current | RCD Breaker | Copper Cable (YJV) | Aluminum Cable (YJLV) | Phase |
|---|---|---|---|---|---|
DC 7kW | ≤38A | 40A / 2P | 3×6 | 3×10 | Single-phase |
DC 20kW | ≤36A | 40A / 3P/4P | 3×10+2×6 | 3×16+2×10 | Three-phase |
DC 30kW | ≤54A | 63A / 3P/4P | 3×16+2×10 | 3×25+2×10 | Three-phase |
DC 40kW | ≤72A | 80A / 3P/4P | 3×25+2×10 | 3×50+2×25 | Three-phase |
DC 60kW | ≤108A | 125A / 3P/4P | 3×50+2×25 | 3×70+2×35 | Three-phase |
DC 80kW | ≤143A | 160A / 3P/4P | 3×70+2×35 | 3×95+2×50 | Three-phase |
DC 120kW | ≤215A | 250A / 3P/4P | 3×95+2×50 | 3×120+2×70 | Three-phase |
DC 160kW | ≤286A | 315A / 3P/4P | 3×120+2×70 | 3×185+2×95 | Three-phase |
DC 180kW | ≤322A | 350A / 3P/4P | 3×150+2×120 | 2×(3×120+2×70) | Three-phase |
DC 200kW | ≤358A | 400A / 3P/4P | 3×185+2×95 | 2×(3×150+2×70) | Three-phase |
DC 240kW | ≤430A | 500A / 3P/4P | 3×240+2×120 | 2×(3×185+2×95) | Three-phase |
DC 320kW | ≤572A | 630A / 3P/4P | 2×(3×150+2×70) | 2×(3×240+2×120) | Three-phase |
DC 360kW | ≤644A | 800A / 3P/4P | 2×(3×185+2×95) | 2×(3×240+2×120) | Three-phase |
DC 400kW | ≤715A | 800A / 3P/4P | 2×(3×185+2×95) | 2×(3×240+2×120) | Three-phase |
3.2 Split-type DC Charging Power Cabinet
The table below shows reference cable selection for split-type DC charging power cabinets.
Power | Input Current | RCD Breaker | Main Input Cable | Main Line to Terminal Connection | Ground Cable |
|---|---|---|---|---|---|
240kW | ≤430A | 500A, 3P/4P | ZR-YJV-0.6/1-3×240+2×120 | 1. DC output: ZR-YJV-22-0.6/1-2×95, one set of cables per charging terminal. 2. Auxiliary power: ZR-2×2.5mm², one set of cables per charging terminal. 3. Communication cable: 2×(RVSP-500V 2×1mm²), terminals connected in series and linked to the rectifier cabinet. | ≥35mm² copper wire (for each grounding terminal) |
360kW | ≤644A | 800A, 3P/4P | 2×(ZR-YJV-0.6/1-3×185+2×95) | 1. DC output: ZR-YJV-22-0.6/1-2×95, one set of cables per charging terminal. 2. Auxiliary power: ZR-2×2.5mm², one set of cables per charging terminal. 3. Communication cable: 2×(RVSP-500V 2×1mm²), terminals connected in series and linked to the rectifier cabinet. | ≥35mm² copper cable |
480kW | ≤860A | 2×500A, 3P/4P | 2×(ZR-YJV-0.6/1-3×240+2×120) | 1. DC output: ZR-YJV-22-0.6/1-2×95, one set of cables per charging terminal. 2. Auxiliary power: ZR-2×2.5mm², one set of cables per charging terminal. 3. Communication cable: 2×(RVSP-500V 2×1mm²), terminals connected in series and linked to the rectifier cabinet. | ≥35mm² copper cable |
600kW | ≤1072A | 3×400A, 3P/4P | 3×(ZR-YJV-0.6/1-3×185+2×95) | 1. DC output: ZR-YJV-22-0.6/1-2×95, one set of cables per charging terminal. 2. Auxiliary power: ZR-2×2.5mm², one set of cables per charging terminal. 3. Communication cable: 2×(RVSP-500V 2×1mm²), terminals connected in series and linked to the rectifier cabinet. | ≥35mm² copper cable |
720 kW | ≤1287 A | 3×500 A, 3P/4P | 3×(ZR-YJV-0.6/1-3×240+2×120) | 1. DC output: ZR-YJV-22-0.6/1-2×95, one cable set per charging terminal. 2. Auxiliary power: ZR-2×2.5mm², one cable set per charging terminal. 3. Communication cable: 2×(RVSP-500V 2×1mm²), terminals connected in series to the rectifier cabinet. | ≥35mm² copper cable |
960 kW | ≤1716 A | 4×500 A, 3P/4P | 4×(ZR-YJV-0.6/1-3×240+2×120) | 1. DC output: ZR-YJV-22-0.6/1-2×95, one cable set per charging terminal. 2. Auxiliary power: ZR-2×2.5mm², one cable set per charging terminal. 3. Communication cable: 2×(RVSP-500V 2×1mm²), terminals connected in series to the rectifier cabinet. | ≥35mm² copper cable |
4. Charging station construction cost optimization
Cable costs account for a significant portion of EV charging station infrastructure investment, and optimizing cable design can significantly reduce total project costs.
Willdigits offers a neutral-free wiring solution, eliminating the need for a neutral conductor in certain configurations, reducing cable material usage and overall construction costs while maintaining compliance and safety.
5. Conclusion
Precise cable selection based on charging power and system topology ensures safe, efficient, and cost-effective deployment of EV charging stations. By optimizing design solutions, operators can significantly reduce infrastructure investment while maintaining high performance.
